AZ494AMTR-E1 Diodes Incorporated

Data Sheet PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494A/C General Description Features The AZ494A/C is a voltage mode pulse width modula- Stable 4.95V/5V Reference Voltage Trimmed to tion switching regulator control circuit designed pri- 1.0% Accuracy marily for power supply control. Uncommitted Output TR for 200mA Sink or Source Current The AZ494A/C consists of a reference voltage circuit, Single-End or Push-Pull Operation Selected by two error amplifiers, an on-chip adjustable oscillator, a Output Control dead-time control (DTC) comparator, a pulse-steering Internal Circuitry Prohibits Double Pulse at Either control flip-flop, and an output control circuit. The pre- Output cision of voltage reference (V ) is improved up to REF Complete PWM Control Circuit with Variable 1% through trimming and this provides a better output Duty Cycle voltage regulation. The AZ494A/C provides for push- On-Chip Oscillator with Master or Slave Opera- pull or single-ended output operation, which can be tion selected through the output control. Applications The difference between AZ494A and AZ494C is that they have 4.95V and 5V reference voltage respectively. SMPS The AZ494A/C is available in standard packages of Back Light Inverter DIP-16 and SOIC-16. Charger DIP-16 SOIC-16 Figure 1. Package Types of AZ494A/C Sep. 2009 Rev. 1. 4 BCD Semiconductor Manufacturing Limited 1 Data Sheet PULSE-WIDTH-MODULATION CONTROL CIRCUITS AZ494A/C Pin Configuration M/P Package (SOIC-16/DIP-16) 1IN + 2IN + 1 16 1IN - 15 2IN - 2 3 FEEDBACK 14 REF DTC 4 OUTPUT CTRL 13 5 12 CT V CC 6 RT 11 C2 7 10 GND E2 C1 8 9 E1 Figure 2. Pin Configuration of AZ494A/C (Top View) Output Function Control Table Signal for Output Control Output Function V = GND Single-ended or parallel output I V = V Normal push-pull operation I REF Functional Block Diagram OUTPUT CTRL 6 13 8 RT C1 5 Oscillator Pulse-Steering CT Flip-Flop Q1 Dead-Time Control Comparator 9 E1 D 4 C2 DTC + 11 CK 0.12V Q2 Error Amplifier 1 + 10 PWM E2 1 Comparator 1IN + + 2 1IN - 12 V CC Error Amplifier 2 16 2IN + + Reference 14 REF Regulator 15 2IN - 0.7mA 7 GND 3 FEEDBACK Figure 3. Functional Block Diagram of AZ494A/C Sep. 2009 Rev. 1. 4 BCD Semiconductor Manufacturing Limited 2